1. Field of the Invention
The present invention relates to a semiconductor structure and a manufacturing method thereof, and more particularly, to a semiconductor structure including metal gates at least partially formed by a selective metal deposition process and a manufacturing method thereof.
2. Description of the Prior Art
The development of semiconductor integrated circuit technology progresses continuously and circuit designs in products of the new generation become smaller and more complicated than those of the former generation. The amount and the density of the functional devices in each chip region are increased constantly according to the requirements of innovated products, and the size of each device has to become smaller accordingly. For instance, it is more difficult to form a source/drain contact between gate electrodes when the spacing between the gate electrodes becomes smaller. In addition, the gate electrode may be exposed easily during the etching process for forming an opening in an isolation material between the gate electrodes, and a short circuit may occur between the exposed gate electrode and a source/drain contact subsequently formed. Therefore, it is necessary to modify the process and the structural design for improving related process window and enhancing production yield.